Weak‐Acid Ion Exchange for Removing Barium, Radium, and Hardness

Weak‐acid resin in the hydrogen form was found to effectively remove barium, radium, and hardness, without increasing the sodium content of the product water. The maximum capacity of the weak‐acid resin was about 2.3 times that of strong‐acid resin, and much less spent regenerant per unit volume of water treated was produced from a weak‐acid column than from a strong‐acid column. There are, however, some disadvantages to weak‐acid ion exchange swelling of the resin during exhaustion, the need to use acid‐resistant materials, the inability to remove noncarbonate hardness, the necessity of stripping carbon dioxide from the product water and adjusting the pH, and the probable higher cost.